Tire mold



June 16, 1925. 1,542,802

T. MIDVGLEY 5 TIRE MOLD Fed Nov. 3 1924 I N VEN TOR.

Patented Julie r16, 1925.

UNITEDisTATEs 1543802, PATENT oFF'lcE.

THo'MAsnInGLEY, or HAMPDEN. MASSACHUSETTS, AssIGNoE To THE Ersx RUBBER COMPANY, or cHrcorEE FALLS, VAamssACHUsETTs, A Co-EroEATIoN or Massa- CHUSETTS.

TIRE MOLD.

`.application med November 3, 1924. serialimfnmze.

To all whomv it may concern: i

, Be it know-n that I, THOMAS MIDGLEY; a citizen of the United. Statesof America, residing at Hampden," in the county of y Hampden and Stateof Massachusetts, have invented certain new and useful Improvements in Tire Molds, of which the following is a specification. This invention relates to molds for use inr l0 the vulcanization of tire casings, and has for its object the .improvements ofsuch molds of this class as are .constructed from sheet metal. Aside from certain constructional improvements, the nature of which can be described. in connection with the drawings better than could be done here, the present invention in one modificationprovides registering means integral with the mold which insure that ay stack of molds in 20 a heater will be straight and vthat each mold will therefore receive a directand sym` metrica] pressure.

Referring now to the drawings, Fig. 1 is a section of a mold embodying certain features of my invention, one side being removed from the tire;

Fig. 2 is a fragmentary side elevation thereof; l

Fig. 3 is a detail showing the manner in l0 which the side platesare manufactured;

Fig. 4 is a section of two molds showing a modiication providing registering means 0 i yto insure accurate allgnment of successive for insuring proper alignment of the molds when the are stacked in a heater; and

Fig. 5 1s a detail of another modification.

The bead portions' 10 of the tire 11 are shown "as confined` between lbead rings 12 of the usual type, held assembled by bolts 13.

' 'Ihe tire itself is supported on an expansible annular bag 14 into which fluid pressure may be introduced to force the tire out into the mold. The side plates of the mold arek each formedof a single piece of sheet metal, tirst pressed as shown by dotted lines in 45 Fig 3, then machined as indicated byV full lines in that figure, andl linally machined with the desired tread design and other markings as shown in Fig. 1. Lettering may conveniently be impressed in the side plates by a stamping process before the molds are machined. Each side plate has a curved portion 15 shaped to fit the outside of the tire, an inwardly extending prying flange 16, and a ris-entrant portion between these two parts machined at 17 to the vshape larger sizes additional bracin "tained, as shown in Fig. 5, y a pin 31 of the tire and at 18 to the outer shapeof the bead molding rings 12. For strength `a wire or rod 19 may be inserted in the groove 2() of the re-entrant portion and 'welded in place as at 21. Theouter portion 00 of the side plate is bent over to overlie the tread of the tire and carries the tread design in intaglio at 22.

A ring 23 isk attached to each of the side plates, one ring being cut away at 24` and 05 the other at 25 so that 'the two halves of the mold will assemble in proper registrap tion. `The rings are bent outwardly to form bearing lianges 26, the surfaces of which are in line with flattened surfaces 27 and 28 of the side plates. VTo secure thelings to the side plates they'may be welded along their meeting lines 29 and 30. In molds of the may bev obriveted to the ring at 32 and welded tothe plate at 33. Steam vents to permit circulation over the greatest possible area of the mold surface may be obtained by grooves 34 running radially of the mold and other grooves, if desired, running circumferentially as is customary with thensualcast molds. Holes `35 serve both to facilitate circulation of steam and to drain off con-. densedff steann` or cooling water when the mold is removed `from the vulcanizing press. In Fig. 4 a modification is shown, designed molding rings. When the self-registering 101,),v

feature is desired, however, one of the flanges 16 may be bent outwardly-at 38, while the other is cut off short as at 39. As shown in Fig. 4 the two flangespof adjacent molds interfit to produce an accurate 106 alignment of the molds when plled one on another. g

Having thus described my invention, I claim:

i 1. A tire mold comprising a pair of side 110 plates each formed of a single metal sheetl curved to conform to the shape of the tire, a ring ixcd to each of said plates near its outer periphery and bent parallel to the plane of the mold to present a lateral thrust-receiving flange, and bead rings adapted to grasp the bead portion of the tire to be vulcanized, the side plates overlying the sides of the bead rings to present additional lateral thrust-receiving surfaces and having re-entrant bends adapted to lit around the outer circumferences of the bead rings.

2. A tire mold having a pair of side plates, each constructed of a single piece of sheet metal curved to conform to the tread and side of the tire and extending inwardly past the beads of the tire to form a prying ange, said piece having a re-entrant bend adapted to lit around a bead molding ring, and a lling of additional metal located in and Welded to said re-entrant bend.

3. A tire mold having a pair of opposed sheet metal side plates, one having an out- Wardly bent flange at its inner periphery and the other being cut away at a circumference corresponding to the outer circumference of the flange, vvhereby When a plurality of molds are stacked one upon another they will intert into axial alignment.

THOMAS MIDGLEY. 

